8
Specific Organic Coatings
To select asuitable coating system,itisnecessary to determine the environmentalconditions around the structure to be painted.Ifthe coating is to be
appliedt oa ne xterior surface, are there nearby chemical plants, pulp and
paper mills, or heavy industries that might provide airborne pollutants? Is
the objective of the coating to provide an aestheticappearance or to provide
maximum corrosion protection that willlimit the colorstothe normal grays,
whites, and pastels of the most corrosion resistant coatings? Will the surface
be predominantly wet (salt or freshwater) or exposed to ac hemical contaminant(acid or alkaline)?Isthe environment predominantly aweathering
environment subject to heat, cold, daily or seasonalt emperature changes,
precipitation, wind (flexing), exposure to sunlight, or detrimental solar rays?
Will the surface be exposed to occasional spells of acorrosive or solvent?After
the environmental conditions of the area have been defined, asuitable resistant coating can be selected. Characteristics, corrosion resistance, limitations,
and uses of the common generic types of coatings will be discussed.
8.1T hermoplasticR esins
Protective coatings formulated from theser esins do not undergo any
chemical changef romt he time of application until the final properties of
ad ried protective film have been attained. The film is formed by the
evaporation of the solvent,c oncentrating the binder/pigment solution and
causing it to precipitate as acontinuous protective film.
8.1.1 Vinyls
These arep olyvinyls dissolved in aromatics, ketones, or esters.
1. Resistance: Insoluble in oils,g reases, aliphatic hydrocarbons, and
alcohols; resistant to water and salt solutions; at room temperature,
resistant to inorganic acids and alkalies;fire resistant.
CAT8247—CHAPTER 8—17/10/2006—14:20—SRIDHAR—XML MODEL B–pp. 487–507
487
Specific Organic Coatings
To select asuitable coating system,itisnecessary to determine the environmentalconditions around the structure to be painted.Ifthe coating is to be
appliedt oa ne xterior surface, are there nearby chemical plants, pulp and
paper mills, or heavy industries that might provide airborne pollutants? Is
the objective of the coating to provide an aestheticappearance or to provide
maximum corrosion protection that willlimit the colorstothe normal grays,
whites, and pastels of the most corrosion resistant coatings? Will the surface
be predominantly wet (salt or freshwater) or exposed to ac hemical contaminant(acid or alkaline)?Isthe environment predominantly aweathering
environment subject to heat, cold, daily or seasonalt emperature changes,
precipitation, wind (flexing), exposure to sunlight, or detrimental solar rays?
Will the surface be exposed to occasional spells of acorrosive or solvent?After
the environmental conditions of the area have been defined, asuitable resistant coating can be selected. Characteristics, corrosion resistance, limitations,
and uses of the common generic types of coatings will be discussed.
8.1T hermoplasticR esins
Protective coatings formulated from theser esins do not undergo any
chemical changef romt he time of application until the final properties of
ad ried protective film have been attained. The film is formed by the
evaporation of the solvent,c oncentrating the binder/pigment solution and
causing it to precipitate as acontinuous protective film.
8.1.1 Vinyls
These arep olyvinyls dissolved in aromatics, ketones, or esters.
1. Resistance: Insoluble in oils,g reases, aliphatic hydrocarbons, and
alcohols; resistant to water and salt solutions; at room temperature,
resistant to inorganic acids and alkalies;fire resistant.
CAT8247—CHAPTER 8—17/10/2006—14:20—SRIDHAR—XML MODEL B–pp. 487–507
487